marinepure (leaching alum?) vs pond matrix vs ????

[nitrodude]

Im looking for good filtration media to put in my sump on a tank for stingrays

I like the marinepure 8x8x4 block, however after doing some research ive found people who run them and have gotten triton tests have high aluminum concentration. Im not sure if higher then normal concentrations of aluminum would be a problem for stingrays.

I currently have a gallon of pond matrix in the sump, that i havnt had any issues with. This stuff also supposibly reduces nitrates as well as the block.

And im open to other options for biomedia if theres something better then these two?
And opinions on marinepures block and the aluminum issues.

 

[Cory]

Personally i think regular sand or live rock works and is proven.are you saying aluminium?

 

[nitrodude]

Aluminum-aluminium same thing :D

Im looking for the most beneficial bacteria for the space provided. A single 8x8x4 marinepure block is supposibly capable of running up to a 250g tank all by itself.

 

[Cory]

I wouldnt trust it then. Try something else like fused glass or live rock is fine by itself.

 

[ksfulk]

I have a pair of marinepure blocks for my tank, and you do see elevated levels of aluminum, but the levels arent near what @Randy Holmes-Farley was at when he started to see detrimental issues with leather corals.

It may be worth looking into issues with aluminum sensitivity in stingrays, but i dont think the amount of Al thats present is detrimental

 

[nitrodude]

I know stingrays and sharks are both sensitive to metals, but im unsure how much aluminum it would take to bother them.

Any idea if carbon removed the aluminum?